Benchmark EEb

Maria's Market

To: Consultants
From: Beth Richards
Subject: Maria's Market

Please complete the following chart, so we can make decisions about the solar energy system we will need for Maria's Market.

Appliance	Watt Rating (watts)	Time Used (per day)	Watt-hours Needed
Lights	15 W	4 h
Refrigerator	120 W	9 h
Blender	75 W	40 min
Total

1. The solar panels we have been testing each provide 50 watts of peak power. How many panels will we need for the market?
2. The batteries we have been using in Central America to store energy from our solar panels are not perfect. In some cases we can get out only 50% of the energy that we store in them. The remaining energy is converted into heat energy, not electrical energy. Help me determine the best choice for batteries, if she wants to be prepared for five consecutive rainy days.

Battery Capacity	Efficiency	Cost per Battery
1500 watt-hours	50%	$55.00
1200 watt-hours	60%	$45.00
1000 watt-hours	70%	$50.00
800 watt-hours	75%	$40.00

A Room in a HouseChoose a room in the house to the right. Make two (2) reasonable estimates of the time each appliance would be turned on. Make a table to show the cost of each estimate.

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